Filamentary stacked triode



Aug. 4, 1959 L. FEINSTEINV 2,898,503

FILAMENTARY sTAcKED 'TRIODE Filed sept. 15, 1954 'w 25a v 25C i; gl: A

as: as 4 4 INVENTOR I9 LESTER FEINSTEIN ATTORNEY Patented Aug. 4, 1959 FILAMENTARY STACKED TRIODE Lester Feinstein, Freeport, N.Y., assign'or, by mesne assignments, to Sylvania Electric Products Inc., Wilmington, Del., a corporation of Delaware Application September 15, 1954, Serial No. 456,122 1S Claims. (Cl. 313-238) This invention relates to electron discharge devices and more particularly to electrode assemblies for such devices, and the means for supporting these assemblies within their envelopes.

Heretofore, electrodes employed in electron discharge devices of the type which has the operating areas of the electrodes disposed along the longitudinal axis of the devices have been supported within their envelopes by means of insulating spacers and by electrode leads extending from the stem. In this type construction, it has been necessary to make the assembly by mounting each electrode in proper sequence on a support and subsequently securing the elements against displacement with respect to one another by use of a spacer. These mount constructions are costly to make and lack the ruggedness required for many present day applications. The proper lateral support against sidewise motion of the electrodes is particularly deficient in this type of tube.

It is among the objects of this invention to avoid the above objections and to provide for a ruggedly constructed electron tube which can be made easily and cheaply.

Itis a further object of this invention to provide for an integral electrode assembly.

It is a still further object to provide means for elfectively and securely mounting the electrode assembly within the envelope of an electron tube.

The foregoing and other objects of this invention are achieved by the provision of an integral electrode assembly which can be mounted as a unit upon longitudinally extending support rods, thereby providing for alignment and rigid support of the assembly Within the envelope. These support rods are fused into the envelope at both of their longitudinal extremities.

Certain preferred details of this construction and further advantages will be apparent, and the invention itself will be better understood, by reference to the following description taken in conjunction with the following drawings, wherein Fig. 1 is a longitudinal sectional view of an electron tube embodying this invention.

Fig. 2 is a similar view taken at right angles to the section of Fig. 1, with parts broken away to expose inner portions.

Fig. 3 is a horizontal sectional View along line 3 3 of the electron tube shown in Fig. 1.

Fig. 4 is a similar view along line 4-4 of the electron tube shown in Fig. 2.

Referring to the drawings more in detail, the electron tube 11 is shown as having an envelope 13, an integral electrode assembly 15, support rods 17, and rivets 21. Any conventional method of attaching rods 17 to the rivets 21, such as welding, may be used. These rods 17 are sealed within the envelope 13 at their longitudinal extremities. Referring to Fig. 2, two support rods 17 are shown. This is the preferred construction," although one rod may adequately support the electrode assembly 15, in some instances. These rods 17 are bowedto facilitate Welding the rods 17 to rivets 21 at the mid-portions of the rods, while still allowing the ends of the rods to be suciently close at the top seal to have adequate fusion space, and at the lower seal to be in proper spaced alignment with one another at the base. This spaced alignment s necessary since rods 17 have the dual function of supporting electrode assembly 15 within the envelope and which includes an anode, and serving as the outside electrical leads for said anode. In addition, the bowed shaped of rods 17 provides for a more rigid support. The two rods are welded to the four rivets 21, thereby providing a four position support for electrode assembly 15. This four position support securely axes the electrode assembly 15, thereby greatly minimizing possible movement of the assembly. This type of construction is particularly advantageous for minimizing lateral movement of electrode assemblies whose electrodes have their operating areas disposed alongthe axis of the electron tube.

The integral electrode assembly 15 comprises a lilamentary cathode 23, a grid structure 25, insulating spacers 27 and 29, an anode 31, previously referred to, cathode tensioning device 33, and securing or clenching means such as rivets 2l. Aiixed to one of the anode elements, as by welding, is getter 35. The integral electrode assembly 15 is constructed as a unit, and subsequently mounted as a unit on support rods 17. The filamentary cathode 23 transverses grid structure 25, and is aligned therewith by means of spacer 29. Grid structure 25 abuts insulating spacers 27 and 29 and is properly spaced thereby from the anode 31. These electrodes are stacked on and rigidly held together by means of rivets 21.

As shown more `clearly in Fig. 2, grid structure 25 comprises a centrally apertured frame 25a having lateral wires 25h aixed to both planar surfaces of the frame and extending across the central aperture. At the longitudnal extremities of frame 25a and in line with the l central aperture, are offset portions 25C. These offset portions provide spaces for facilitating passage of the fllamentary cathode 23 past the edges of the frame 25av and into the space intermediate the lateral wires 25b to prevent shorting cathode 23 with the metallic frame 25a. Fig. 1 illustrates the relationship of offset portions 25a` to cathode 23. The grid frame 25a has apertures therein providing for passage of rivets 21 therethrough. These apertures are larger than the diameter of the rivet, as shown in Fig. 4, thus preventing the grid from shorting with the rivets 21. Insulating bushings about rivets 21 at the grid level may be used, if desired.

Insulating spacer 27 comprises two rectangular strips, each strip interposed between the grid frame 25a and the anode 31 and on each side of the longitudinal axis of the grid structure central aperture. The spacer strips have apertures to allow passage of rivets 21 therethrough. In-v sulating spacer 29 is a rectangular member having a window portion therein over the area of coverage of grid lateral wires 25b. This window provides for an unrestricted passage of electrons from cathode 23 to anode 31. At the longitudinal extremities of spacer 29 are bridge members 29a and 29b. These bridge members are semi-cylindrical ribs integral with the shorter ends of the rectangular member and extending therealong. As seen in Fig.r l, these `insulating bridge'members locate and align the lamentary cathode within grid structure 25. Q Within the spacer 29 and adjacent the bridge members 29a and 29h are apertures for receiving pins 41` and 45. In addition, four other apertures are provided in spacer 29 for receiving the rivets 21. Pin 45 serves as a support for lament tensioning device 33, and pin .41 serves as a support for a cathode tab 43.

Anode 31 comprises two rectangular half-plates whichl are separated from grid structure 25-by means of the.v spacers 27 and 29. The anode is secured to the assembly 15 bynieans of the rivets 21. One half-plate is associated with those heads of the rivets 21 which are welded to the support rods 17. The other half-plate abuts the other heads of the rivets. Y

The lamentary cathode 23 is attached tothe assembly by means of tensioning Adevice 33 and cathode tabs 43. The cathode is looped over tensioning device 33 and welded to tabs 43, thereby traversing the entire longitudinal length of the electrode assembly 15. The offset prtions 25C allow passage of the cathode past the grid frame. The support points of the cathode with tension device 33 and tabs 43 are positioned such that when thc cathode is supported at these points, it must contact the periphery of bridge members 29a and 29b, thereby becoming spacedly aligned with respect to grid lateral wires ZSb. Figs. 3 and 4 show more clearly the relationship of cathode 23, grid frame offset portions 25e, and spacer bridge members 29a and 29b. The anode 31 is connected to its electrical supply via the rivets, the support rods 17 and appropriate stern leads 19. Cathode 23 is connected to other stem leads 19, via the cathode tabs 43, and pins 41, and grid 25 is connected directly to still other stem leads 19.

An electron tube made in accordance with the invention is compact and can withstand shock and vibration without being subjected to any appreciable amount-of microphonics. In addition, the integral electrode assembly can be quickly mounted on the rods both etiiciently and accurately.

Although one embodiment of this invention has been described herein, it will be understood that the invention is not limited thereto since the structure and arrangement of the described parts may be modied without departing from the spirit and scope of the invention as defined by the appended claims.

What is claimed as new is:

1. An electron tube comprising an envelope with opposing ends, an integral electrode assembly comprising electrodes and spacers therebetween with the electrodes and spacers held in xed relationship to each other, rods secured within the ends of the envelope and bridging the space therebetween, and said integral electrode assembly being mounted as a unit upon the rods and fastened thereto.

2. An electron tube comprising an envelope, an integral electrode assembly having electrodes and spacers, means for securing the electrodes and spacers together, and support rods, each of said rods being aixed to each end of the envelope, and the electrode assembly being mounted as a unit upon the rods by said securing means.

3. An electron tube comprising an envelope, an integral electrode assembly having electrode and spacer elements, means for securing said elements together, and support rods having bowed sections, each of said rods being affixed to each end of the envelope adjacent said bowed sections, said electrode assembly being mounted as a unit upon the support rods intermediate said bowed sections.

4. An electron tube comprising an envelope, an integral electrode assembly having electrode and spacer elements, means for securing said elements together, and support rods having bowed sections, each of said rods being affixed to each end of the envelope adjacent said bowed sections, said electrode assembly being mounted as a unit upon the support rods intermediate said bowed sections by said securing means. I Y

5. An electron tube comprising an envelope, an integral electrode 'assembly having electrode and spacer elements, means for securing said elements together, and support rods, each of said rods being aiiixed to each end of the envelope, said electrode assembly being mounted as a unit upon the support rods at a multiplicity of spaced points by said securing means.

6. An electron tube comprising an envelope, an iintegral electrode assembly having electrode and spacer elements, means for securing said elements together,r and Support rods, each of said rods being aliixed to each enc'l of the envelope, said electrode assembly being mounted as a unit upon the support rods at a multiplicity of spaced points by said securing means, at least one of the points being on one rod, and another point being on the other rod.

7. An electron tube comprising an envelope, an integral electrode assembly having electrode and spacer elements, means for securing said elements together, and support rods having bowed sections, each of said rods being affixed to each end of the envelope adjacent said bowed sections, said electrode assembly being mounted as a unit upon the support rods intermediate said bowed sections and at a multiplicity of spaced points by said securing means.

8. An electron tube comprising an envelope, an integral electrode assembly having electrode and spacer elements, means for securing said elements together, and support rods, each of said rods being atlixed to each end of the envelope, said electrode assembly being mounted as a unit upon the support rods and at four positions dening a rectangle by said securing means.

9. An electron tube comprising an envelope, an integral electrode assembly having electrode and spacer elements, means for securing said elements together, and support rods having bowed sections, each of said rods being atlixed to each end of the envelope adjacent said bowed sections, said electrode assembly being mounted as a unit upon the support rods intermediate said bowed sections and at four positions defining a rectangle by said securing means.

10. An electron tube comprising an envelope, an integral electrode assembly having insulating spacer elements and also cathode, grid and anode elements, means for securing all of said elements together, and support rods having bowed sections, each of said rods being atlixed to each end of the envelope adjacent said bowed sections, said electrode assembly being mounted as a unit upon the support rods intermediate said bowed sections and at a multiplicity of points by said securing means, the support rods being electrically conncctedto the anode and serving as electrical leads for said anode.

11. An electron tube comprising an envelope, an integral electrode assembly Ihaving insulating spacer elements and also cathode, grid and anode elements, means for securing said elements together, and support rods having bowed sections, each of said rods being affixed to each end of the envelope adjacent said bowed sections,

said electrode assembly being mounted as a unit upon the support rods intermediate said bowed sections and at four positions defining a rectangle by said securing means, the support rods being electrically connected to the anode and'serving as electrical leads for said anode;

12. An electrode mount for an electron tube comprising an integral electrode assembly having insulating spacer elements, and also cathode, grid and anode elements,

j means for securing the elements together, and support rods; the spacer, grid and anode elements having apertures therein for receiving the securing means, said electrode assembly being mounted as a unit upon the support rods by the securing means.

13. An electrode mount for an electron tube coini prising an integral electrode assembly having insulating spacer elements, and also cathode, metallic frame grid and anode elements, means having terminal portions for securing the elements together, and support rods; the spacer, grid and anode elements having apertures therein cooperating with the securing means, each of said grid apertures being of a diameter substantially greater than the diameter of said means, thereby preventing electrical contact of the metallic frame with said means, said electrode assembly being mounted as a unit upon the support rods by connections with said terminal portions of the securing means. i

14. An electrode mount for van electron tube comprising an integral electrode assembly having insulating spacer elements, and also cathode, metallic frame grid and anode elements, means having terminal portions for securing the elements together, and support rods having bowed sections; the spacer, grid and anode elements llaving apertures therein cooperating with the securing means, each of said grid apertures being of a diameter substantially greater than the ydiameter of said means, thereby preventing electrical contacts of the metallic fname with said means, said electrode assembly being mounted as a unit upon the support rods at four positions delning a rectangle by connections with said terminal portions of the securing means, all of said positions being intermediate the bowed sections of said support rods.

15. An integral electrode assembly comprising a grid element having a frame with lateral wires thereon, a iilamentary cathode element disposed lbetween said lateral wires, insulating spacer elements associated with each major face of said frame, half-plate anode elementsassociated with each spacer, and means for securing said elements together; the grid, spacer, and anode elements having apertures therein for cooperating with said means to affect alignment of said elements with respect to one another.

16. An electrode assembly including lamentary cathode, grid structure, and anode elements, insulating spacers, and means for seeming said elements and spacers together, said grid structure comprising a frame having a central opening therein, lateral wires supported on both major surfaces of the frame and extending across said opening, and end portions of the frame, both oiset in the same direction, said cathode being located between the lateral wires and traversing the frame at said offset portions.

17. An electrode assembly including filamentary cathode, grid structure, land anode elements, insulating spacers, and means for securing said elements and spacers together, said grid structure comprising a frame having a central opening therein, lateral wires supported on both major surfaces of the frame and extending across said opening, and end portions of the frame, both oist in the same direction from the remainder of the frame, one of said insulating spacers having bridge members located beyond the confines of the grid structure,`said cathode being located between the lateral wires and traversing the frame at said offset portions, said bridge members cooperating with the cathode for aligning said cathode with respect to the grid lateral wires.

18. An electrode assembly including iilamentary cathode, cathode tensioning device, cathode tab, grid structure, and anode elements, insulating spacers, and means for securing said elements and spacers together, said grid structure comprising a frame having a central opening therein, lateral wires supported on both major surfaces of the frame and extending across said opening, and end portions of the frame, both offset in the same direction from the remainder of the frame, one of said insulating spacers having bridge members located beyond the contines of the grid structure, said cathode being supported at one end by the tensioning device and at the other end by the cathode tabs, the points of support of the tensioning device and cathode tabs lying within the outer surface of the bridge members, and said cathode being located between the lateral wires and traversing the frame at said otfset portions, said bridge members cooperating with the cathode for aligning said cathode with respect to the grid lateral Wires.

References Cited in the file of this patent UNITED STATES PATENTS 1,624,451 Weinhart Apr. 12, 1927 1,993,804 Powers Mar. 12, 1935 2,204,217 Herriger June 11, 1940 2,473,547 Schmidt June 21, 1949 FOREIGN PATENTS 690,420 Great Britain Apr. 22, 1953 

